Add transcoder for stake transaction metadata. Add support for approve component for this new txn type.

Author: Lazy Nina

src/app/approve/approve.component.ts

@@ -39,6 +39,7 @@ import {
   TransactionSpendingLimit,
   TransactionMetadataRegisterAsValidator,
   TransactionMetadataUnregisterAsValidator,
+  TransactionMetadataStake,
 } from '../../lib/deso/transaction';
 import { ExtraData } from '../../types/identity';
 import { AccountService } from '../account.service';
@@ -597,6 +598,18 @@ export class ApproveComponent implements OnInit {
       case TransactionMetadataUnregisterAsValidator:
         description = 'unregister as a validator';
         break;
+      case TransactionMetadataStake:
+        const stakeMetadata = this.transaction
+          .metadata as TransactionMetadataStake;
+        const stakeValidatorPublicKey = this.base58KeyCheck(
+          stakeMetadata.validatorPublicKey
+        );
+        publicKeys = [stakeValidatorPublicKey];
+        const stakeAmountNanos = this.hexNanosToUnitString(
+          stakeMetadata.stakeAmountNanos
+        );
+        description = `stake ${stakeAmountNanos} $DESO to ${stakeValidatorPublicKey}`;
+        break;
     }
 
     // Set the transaction description based on the description populated with public keys.
@@ -617,6 +630,8 @@ export class ApproveComponent implements OnInit {
     return bs58check.encode(Buffer.from([...prefix, ...keyBytes]));
   }
 
+  // TODO: create hexBaseUnitsToUnitString function to support proper
+  // DAO Coin base unit conversions.
   hexNanosToUnitString(nanos: Buffer): string {
     return this.nanosToUnitString(parseInt(nanos.toString('hex'), 16));
   }

src/app/identity.service.ts

@@ -37,6 +37,7 @@ import {
   TransactionMetadataUpdateProfile,
   TransactionMetadataRegisterAsValidator,
   TransactionMetadataUnregisterAsValidator,
+  TransactionMetadataStake,
 } from '../lib/deso/transaction';
 import { SwalHelper } from '../lib/helpers/swal-helper';
 import { AccessLevel, PublicUserInfo } from '../types/identity';
@@ -522,6 +523,7 @@ export class IdentityService {
       case TransactionMetadataDAOCoinLimitOrder:
       case TransactionMetadataRegisterAsValidator:
       case TransactionMetadataUnregisterAsValidator:
+      case TransactionMetadataStake:
         return AccessLevel.Full;
 
       case TransactionMetadataFollow:

src/lib/bindata/transcoders.ts

@@ -96,6 +96,26 @@ export function Optional<T>(transcoder: Transcoder<T>): Transcoder<T | null> {
   };
 }
 
+export function BoolOptional<T>(
+  transcoder: Transcoder<T>
+): Transcoder<T | null> {
+  return {
+    read: (bytes: Buffer) => {
+      const existence = bytes.readUInt8(0) != 0;
+      if (!existence) {
+        return [null, bytes.slice(1)];
+      }
+      return transcoder.read(bytes.slice(1));
+    },
+    write: (value: T | null) => {
+      if (value === null) {
+        return Buffer.alloc(1);
+      }
+      return Buffer.concat([Buffer.alloc(1, 1), transcoder.write(value)]);
+    },
+  };
+}
+
 export const ChunkBuffer = (width: number): Transcoder<Buffer[]> => ({
   read: (bytes) => {
     let [count, buffer] = bufToUvarint64(bytes);

src/lib/deso/transaction.ts

@@ -2,6 +2,7 @@ import { BinaryRecord, Transcode } from '../bindata';
 import {
   ArrayOf,
   Boolean,
+  BoolOptional,
   ChunkBuffer,
   Enum,
   FixedBuffer,
@@ -609,6 +610,18 @@ export class TransactionMetadataRegisterAsValidator extends TransactionMetadata
 
 export class TransactionMetadataUnregisterAsValidator extends TransactionMetadata {}
 
+export class TransactionMetadataStake extends TransactionMetadata {
+  @Transcode(VarBuffer)
+  validatorPublicKey: Buffer = Buffer.alloc(0);
+
+  @Transcode(Uint8)
+  rewardMethod: number = 0;
+
+  // TODO: We may want a better way to handle uint256s.
+  @Transcode(BoolOptional(VarBuffer))
+  stakeAmountNanos: Buffer = Buffer.alloc(0);
+}
+
 export const TransactionTypeMetadataMap = {
   1: TransactionMetadataBlockReward,
   2: TransactionMetadataBasicTransfer,
@@ -644,6 +657,7 @@ export const TransactionTypeMetadataMap = {
   33: TransactionMetadataNewMessage,
   34: TransactionMetadataRegisterAsValidator,
   35: TransactionMetadataUnregisterAsValidator,
+  36: TransactionMetadataStake,
 };
 
 export class Transaction extends BinaryRecord {